______,Remove the chicken breasts or legs from the stock after 1 hour of cooking and let them stand at room temperature until cool enough to handle.,Discard the skin and pick the meat off the bone, shredding it coarsely and discarding little bones and cartilage as you do.,Return the bones to the stock.,Bring a large saucepan of salted water to the boil.,Crumble the ground beef into a large mixing bowl and sprinkle the bread crumbs, parsley, and grated cheese over it.,Beat the egg with 3/4 teaspoon salt and 1/4 teaspoon pepper until blended, and pour over the beef.,Mix thoroughly with clean hands until evenly blended.,Roll a heaping tablespoon of the meat mixture between your palms to form a 1-inch ball.,Repeat with the remaining meatball mix.,Carefully slip the meatballs into the boiling water and cook 2 minutes.,Remove the meatballs with a wire skimmer or slotted spoon and drain thoroughly.,(The meatball mixture can be prepared and the meatballs formed up to several hours in advance, but keep them refrigerated, and dont poach them until just before serving the soup.),Ladle 8 cups of the chicken stock through a fine sieve into a 4-quart pot.,Bring to a simmer.,Stir in the escarole and chicory and simmer 5 minutes.,Stir the reserved shredded chicken into the pot.,Stir in the poached meatballs and spinach, return to the simmer, and cook until the meatballs are cooked through and all the greens are tender, about 5 minutes.,Season to taste with salt and pepper, remove from the heat, and stir in the provola.,Ladle immediately into warmed soup bowls.